package javacore.draw.javacore;

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;
import javax.swing.Box;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.filechooser.FileNameExtensionFilter;

/**
 * This program lets you read and write image files in the formats that the JDK supports. Multi-file
 * images are supported.
 * 
 * @version 1.02 2007-08-16
 * @author Cay Horstmann
 */
// 该方法分解的GIF图片有问题。
public class ImageIOTest
{
    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run()
            {
                JFrame frame = new ImageIOFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);
            }
        });
    }
}

/**
 * This frame displays the loaded images. The menu has items for loading and saving files.
 */
class ImageIOFrame extends JFrame
{
    public ImageIOFrame()
    {
        this.setTitle("ImageIOTest");
        this.setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        JMenu fileMenu = new JMenu("File");
        JMenuItem openItem = new JMenuItem("Open");
        openItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event)
            {
                ImageIOFrame.this.openFile();
            }
        });
        fileMenu.add(openItem);

        JMenu saveMenu = new JMenu("Save");
        fileMenu.add(saveMenu);
        Iterator<String> iter = writerFormats.iterator();
        while (iter.hasNext())
        {
            final String formatName = iter.next();
            JMenuItem formatItem = new JMenuItem(formatName);
            saveMenu.add(formatItem);
            formatItem.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent event)
                {
                    ImageIOFrame.this.saveFile(formatName);
                }
            });
        }

        JMenuItem exitItem = new JMenuItem("Exit");
        exitItem.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event)
            {
                System.exit(0);
            }
        });
        fileMenu.add(exitItem);

        JMenuBar menuBar = new JMenuBar();
        menuBar.add(fileMenu);
        this.setJMenuBar(menuBar);
    }

    /**
     * Open a file and load the images.
     */
    public void openFile()
    {
        JFileChooser chooser = new JFileChooser();
        chooser.setCurrentDirectory(new File("."));
        String[] extensions = ImageIO.getReaderFileSuffixes();
        chooser.setFileFilter(new FileNameExtensionFilter("Image files", extensions));
        int r = chooser.showOpenDialog(this);
        if (r != JFileChooser.APPROVE_OPTION)
        {
            return;
        }
        File f = chooser.getSelectedFile();
        Box box = Box.createVerticalBox();
        try
        {
            String name = f.getName();
            String suffix = name.substring(name.lastIndexOf('.') + 1);
            Iterator<ImageReader> iter = ImageIO.getImageReadersBySuffix(suffix);
            ImageReader reader = iter.next();
            ImageInputStream imageIn = ImageIO.createImageInputStream(f);
            reader.setInput(imageIn);
            int count = reader.getNumImages(true);
            this.images = new BufferedImage[count];
            for (int i = 0; i < count; i++)
            {
                this.images[i] = reader.read(i);
                box.add(new JLabel(new ImageIcon(this.images[i])));
            }
        }
        catch (IOException e)
        {
            JOptionPane.showMessageDialog(this, e);
        }
        this.setContentPane(new JScrollPane(box));
        this.validate();
    }

    /**
     * Save the current image in a file
     * 
     * @param formatName the file format
     */
    public void saveFile(final String formatName)
    {
        if (this.images == null)
        {
            return;
        }
        Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName(formatName);
        ImageWriter writer = iter.next();
        JFileChooser chooser = new JFileChooser();
        chooser.setCurrentDirectory(new File("."));
        String[] extensions = writer.getOriginatingProvider().getFileSuffixes();
        chooser.setFileFilter(new FileNameExtensionFilter("Image files", extensions));

        int r = chooser.showSaveDialog(this);
        if (r != JFileChooser.APPROVE_OPTION)
        {
            return;
        }
        File f = chooser.getSelectedFile();
        try
        {
            ImageOutputStream imageOut = ImageIO.createImageOutputStream(f);
            writer.setOutput(imageOut);

            writer.write(new IIOImage(this.images[0], null, null));
            for (int i = 1; i < this.images.length; i++)
            {
                IIOImage iioImage = new IIOImage(this.images[i], null, null);
                if (writer.canInsertImage(i))
                {
                    writer.writeInsert(i, iioImage, null);
                }
            }
        }
        catch (IOException e)
        {
            JOptionPane.showMessageDialog(this, e);
        }
    }

    /**
     * Gets a set of "preferred" format names of all image writers. The preferred format name is the
     * first format name that a writer specifies.
     * 
     * @return the format name set
     */
    public static Set<String> getWriterFormats()
    {
        TreeSet<String> writerFormats = new TreeSet<String>();
        TreeSet<String> formatNames = new TreeSet<String>(Arrays.asList(ImageIO.getWriterFormatNames()));
        while (formatNames.size() > 0)
        {
            String name = formatNames.iterator().next();
            Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName(name);
            ImageWriter writer = iter.next();
            String[] names = writer.getOriginatingProvider().getFormatNames();
            String format = names[0];
            if (format.equals(format.toLowerCase()))
            {
                format = format.toUpperCase();
            }
            writerFormats.add(format);
            formatNames.removeAll(Arrays.asList(names));
        }
        return writerFormats;
    }

    private BufferedImage[]    images;

    private static Set<String> writerFormats  = getWriterFormats();

    private static final int   DEFAULT_WIDTH  = 400;

    private static final int   DEFAULT_HEIGHT = 400;
}
